1. Field of the Invention
The present invention relates to a paper feeding cassette for use in an office machine such as a printer, copy machine and facsimile machine, and more particularly, to a paper feeding cassette capable of varying paper loading size in accordance with a size a of paper being used.
2. Description of the Related Art
In general, an office machine such as a printer, copy machine, and facsimile machine is provided with a paper feeding tray or cassette (hereinafter, to be referred as “paper feeding cassette”) to load a number of papers. The paper feeding cassette is classified into an exclusive cassette of a fixed size, and a universal cassette of an adjustable size to load paper of different sizes and to freely use the papers irrespective of their sizes.
Because it has a fixed paper loading size intended only for one size paper, the exclusive cassette has an advantage of ensuring that the paper of a desired size is fed. However, the exclusive cassette has a disadvantage in that the cassette needs to be replaced with another exclusive cassette of a different size for a printing operation that uses a paper of a size other than the exclusive cassette initially used. Furthermore, in order to use papers of different sizes, it is necessary to prepare various sizes of paper feeding cassettes to be used exclusively for a corresponding paper size. Therefore, a number of paper feeding cassettes are needed and thus, a space to separately house the paper feeding cassettes may be required.
To overcome the above-described disadvantages of the exclusive cassette, universal cassettes capable of using plural sizes of papers have recently been used.
Referring to FIG. 1, there is shown conventional universal paper feeding cassette which is designed to allow a user to adjust the cassette to meet various sizes of papers by moving one or more side guide members and/or a rear guide member to load the various sizes of papers into the cassette.
The conventional universal paper feeding cassette 1 includes a frame 10 within which one or more papers are loaded, left and right side guide members 20 and 20′ which are located at front opposite sides of the frame 10 to slide crosswise of the papers loaded in the frame 10 while supporting lateral edges of the papers loaded in the frame 10, and a rear guide member 30 which is located at a rear center of the frame 10 to slide lengthwise of the papers loaded in the frame 10 while supporting rear edges of the papers.
The universal cassette 1 is capable of loading papers of different sizes by adjusting the left guide member 20 and the rear guide member 30.
However, because universal cassettes are limited in that the universal cassettes are manufactured in a predetermined range of sizes to increase a loading rate or capacity of office machines during shipping, the universal cassettes may be loaded for papers having a limited size range. Thus, for example, the papers may not exceed A3 size (420×297 mm) and may be adjusted only within the predetermined range of sizes.
Therefore, when papers exceed the A3 size (for example, when Super-A3 size (445×297 mm) papers are required to be printed), there is an inconvenience in that the papers need to be loaded in an abnormal manner or the printing is performed by using a separate exclusive cassette.